Subject 122
by jxchen
Summary: The Luteces begin the 122nd trial of their experiment but find that the Booker DeWitt in this universe is remarkably different. As a professor of theoretical physics at Columbia University, how will Booker #122 combine his military skill and sharp intellect to rescue Elizabeth?
1. Chapter 1

"Oh my, this is quite different." remarked Rosalind as she peered through the tear at the tastefully furnished apartment.

"Are you quite sure this is the correct space-time?"

"I have opened this tear over one hundred times Robert, have I ever brought us to an incorrect space-time?"

"Hmm. No. Then it appears this Booker is quite different."

"Quite."

Booker DeWitt was a light sleeper. Although memories of his ignominious military service had faded as the years passed, the habits and reflexes that made him an excellent cavalryman had not. At the first sound of an unfamiliar voice in his apartment he instinctively grabbed the Mauser pistol that always lay under his pillow and pointed it at the strange couple...dressed in raincoats...standing in a glowing hole in his wall?

"What the hell? Who are you?" Booker demanded.

Neither Lutece paid any attention to the man with the gun as they stepped through the tear. They were drawn to the blackboard in the corner of the room which seemed to be filled with an incomplete derivation of the non-relativistic Schrodinger equation for a single particle moving in an electric field.

"Hmm, that's not quite right." Robert frowned as he picked up the eraser and began erasing the bottom half of the board.

"Hey, put that down!" Booker demanded again as he rose from the bed and walked toward the strange couple. He stopped in mid-stride when he saw what Rosalind had begun to write in the blank space left by Robert. The Mauser slipped out of his hand. Booker could only stare as Rosalind closed the bracket around the Hamiltonian and started work on the wave function.

"My God, that looks right. But how? Only a handful of people in the world understand those symbols. Who are you?" Booker demanded again, this time with much less conviction.

"Why do you ask who," Robert began.

"When the delicious question is how," Rosalind continued.

"For example, how is there a glowing hole in the wall?" Robert finished.

Booker had completely forgotten about the glowing hole in the wall. As he turned to examine it the remarkable analytical mind that had made him one of the preeminent theoretical physicists of his time rapidly cycled through the rational possibilities for its existence, settling upon the only possibility that made sense.

"A stable Tesla tear...remarkable," Booker murmured as he tentatively moved his hand through the tear, collecting raindrops on the back of his hand. The faded letters 'AD' glistened in the light thrown off by the lone lamppost at the end of the pier. The scar from the brand had faded over time along with the pain of loss, but neither had faded entirely. Booker now remembered the last time he had seen a Tesla tear-closing as strange men disappeared through it with his infant daughter. Booker remembered beating his fists raw against the brick wall where the tear had been. Slumping against the wall in defeat. Unable to comprehend what he had seen. Unable to come to terms with the shame of selling his infant daughter to pay for his substance abuse and gambling.

With a quickness uncharacteristic of a man his age Booker leapt toward Robert Lutece with a bloodcurdling yell, which immediately turned into a surprised cry of pain as his right hand passed clean through Robert's unperturbed face and struck the blackboard.

"You missed," Rosalind remarked.

"I believe that depends on your perspective," Robert countered, "he certainly hit something."

"You son of a bitch," Booker spat out through gritted teeth as he nursed his hand, "you daughter-stealing son of a bitch."

"As I remember correctly Mr. DeWitt, you sold your daughter," Robert replied.

"He always sells his daughter," Rosalind elaborated.

"But let's not dwell on your pasts," Robert continued, "we are here to offer a chance at redemption."

Booker had picked up his Mauser from the ground with his left hand but hesitated at the word "redemption". He had been searching for this man and the answers he might have for 20 years. It didn't seem logical to shoot him now, especially since the man appeared to be incorporeal.

Robert smiled as Booker began getting dressed, placing his pistol inside a worn shoulder holster. "We would like to reunite you with your daughter, as penance for our past sins, and to settle this interminable debate I am having with my sister about the nature of reality and choice."

"How, tell me how to get my daughter back."

"But first, we are curious," Rosalind said, "please do tell us what you have done with your life since that day 20 years ago. We had not expected this outcome."

Booker closed his eyes as he began to relive his shameful past.

"After you took my daughter from me I was determined to get her back. Determined enough to get clean. At the time I thought there must be some way I could reopen that portal you and that other man escaped through. Being naive I figured the portal was a result of contemporary technology. So I began to study physics and mathematics. It turned out I had a good mind for science. I sometimes saw strange equations in my dreams, and when I woke I would write them down and find they were new discoveries. Eventually I was offered a position in the physics department at Columbia College. But although I have worked on the problem for many years I have barely begun laying the theoretical foundation for creating a multiverse tear."

"Curious," Rosalind remarked, "perhaps your dreams are a side-effect of exposure to the tear 20 years ago."

"It is not inconsistent with his daughter's gifts," Robert added.

"But this breaks the symmetry. For every Comstock who accepts the baptism there must be a Booker who rejects it. For every Comstock who builds Columbia there must be a Booker who wallows in pain and regret for 20 years. One cannot exist without the other."

"Perhaps not, dear sister. We have only observed 121 previous scenarios. The fact that all of those scenarios contains a Booker who wallows in pain and regret does not negate the existence of a scenario in which Mr. DeWitt channeled his pain and regret into something resembling a productive life. Although apparently the probability of such an outcome is quite low."

"Hmm. Quite low indeed."

Robert turned to address Booker as Rosalind continued to ponder the existence of a Booker DeWitt possessing an IQ greater than that of the average mammal.

"The man who bought your daughter is Zachary Comstock. In the universe through the tear Comstock is the founder of the floating city Columbia. He intends for Anna to succeed him as ruler of Columbia. You will need to find some way to rescue her from this fate. But this conversation is a waste of time. You will most likely experience severe memory loss once you go through the tear...so off we go!"

Booker didn't like the part about severe memory loss. "But if I suffer severe memory loss," he asked, "how will I remember my mission once I pass through the tear?"

"Ah, we have a solution to that." Robert grinned as he produced a cigar box from his jacket pocket and placed it on the nightstand. It was embossed with a shiny brass tag: "Property of Booker DeWitt, 7th Cavalry Wounded Knee".

"This box was designed to provide just enough context for you to fabricate the necessary memories and motivations to rescue your daughter. Much like a scaffold for vine growth."

"That might not be necessary this time," Rosalind countered, "a keen mind can usually survive travel through a tear without serious consequence. Robert passed through his first tear with only slight confusion and brain hemorrhage. We brought the cigar box because we had expected you to be slightly more...ah...apeish than you are. In any case, the tear won't remain stable forever. We should go."

The Luteces stepped back through the tear.

"Are you coming, Mr. DeWitt?" asked Rosalind.

"He does come you know," Robert called out as he walked down the pier to prepare the rowboat.

"Yes I know, it was more of a formality."

"What choice do I have?" Booker thought as he stepped through the tear.


	2. Chapter 2

"Are you going to just sit there?"

"As compared to what, standing?"

"Not standing, rowing."

Booker tuned out the Luteces' incessant banter as he opened the cigar box. His attention was drawn to the grainy photo of a girl.

His little girl.

Anna.

She was the spitting image of her mother: raven-black hair and a strength in her eyes.

Although Booker didn't like admitting it, she appeared to be well cared for. The office of a degenerate drunk in the bad part of town was no place for a little girl to grow up, Booker thought. Who knows where she would have ended up when the loan sharks ran out of patience. Heiress to a city in the sky was a world away from a squalid life in the streets. Perhaps it was for the best. Maybe he should be thanking Comstock for saving both his life and his daughter's.

Booker's train of thought was interrupted as the rowboat came to a stop next to a weathered pier. The lamp of an old lighthouse was visible straight ahead through the fog and rain.

"We've arrived." Rosalind stated.

"Now hold on a second," Booker began, "I'm not getting off this boat until you answer some questions."

Before Rosalind could protest, Booker continued.

"First of all, a city in the sky. How does that work?"

"From this picture of Monument Island," Booker produced the picture of Monument Island from the cigar box and waved it for emphasis, "it appears to be constructed of metal and on the same scale as Lady Liberty. You would need an impossible amount of helium to keep that afloat."

The Luteces glanced at each other.

"This is quite awkward," Rosalind said, "we're not used to being asked insightful questions."

"I suppose some background information wouldn't hurt," she continued, "it is public knowledge after all. The buildings in Columbia are supported by quantum particles suspended in space-time at a fixed height."

That explanation made no sense to Booker, and he wondered if it was a phrase the Luteces had invented to simplify a complex phenomenon for laymen. But he decided it was not a topic worth pursuing. He had more pressing concerns than debating the principles of quantum architecture with two ghosts. Speaking of which...

"Second question. What are you exactly? How are you able to open stable Tesla tears without machinery? How is it you're a ghost when I try to hit you but are able to interact with the world physically when you decide to?"

The Luteces glanced at each other longer this time. The former detective in Booker sensed this was a delay to allow construction of a half-truth.

Rosalind finally relented, "To summarize a long story, we were quite careless during an experiment and now exist outside space-time. As a result, we are able to project as much of ourselves as we desire into any version of reality as well as create links between realities."

Booker considered the consequences of such an existence. "So you have the power of gods. You can end worlds by opening a tear to the core of the nearest star. You see every possible permutation of the multiverse from its moment of creation to its heat death. Omnipotence. Omniscience."

"Omnipotence perhaps," Rosalind countered, "omniscience, not quite. Although we exist outside space-time we are still entities in a higher dimension. This means we cannot simultaneously occupy more than one space-time, and simply by observing a specific reality we cause the future of that reality to become rather uncertain.

"We call that the Lutece uncertainty principle." Robert interjected proudly.

"But yes," Rosalind continued, "despite some limitations we have a frightening amount of power. It's quite fortunate for you we are simply curious scientists."

"Alright, so if you can open tears at will, why don't you just open a tear to where Anna is?"

This question was met with heated argument.

"We can't tell him that," Rosalind began, "it would cause dreadfully unacceptable variance in the subject's decision-space."

"I don't see the harm in it, he'll figure it out soon enough. He's not simple like the others."

"Fine, this entire thought experiment was your idea anyway. If you insist on telling him go ahead, But I won't be a party to experimenter bias."

With a flash of lightning Rosalind disappeared.

After apologizing for his sister's abrupt departure, a slightly flustered Robert fiddled with the buttons on his raincoat as he answered Booker, "It's not that simple. There is a device on Monument Island that prevents us from opening tears."

"What sort of device? How does it work?"

"I'm afraid I can't tell you that."

"What? Why not?"

"It is something you must discover on your own. If you were to understand the nature of the device at such an early juncture it would alter your decision-making and cause this version of reality to go down quite a dangerous path."  
"As it stands we are already courting disaster by discussing this. Now off you go!"

And with that a second bolt of lightning blinded Booker. When he regained his vision Robert had vanished as well, along with the boat oars.

Left with no other option, Booker climbed the wooden ladder and began the walk up to the lighthouse. He had caught the Luteces off guard this time. No doubt they would be better prepared should they decide to reappear to him.


	3. Chapter 3

The storm had intensified by the time Booker reached the double doors of the lighthouse. One door was slightly ajar, a faint light peeking through the opening. Booker gave the door three sturdy knocks. After waiting in vain for a response, he pushed the door open and went inside.

Booker surveyed the scene. The lighthouse keeper was apparently a devout man, as evidenced by the various framed quotes from the Bible scattered around the first floor. At least Booker assumed they were quotes from the Bible. He had not been a religious man even before becoming a scientist, having witnessed too many injustices to believe in a benevolent God.

As he began walking up the stairs to the second level he called out, "Is anyone there? Hello!" not expecting and not receiving a response. He wondered why the Luteces had brought him here. Since his destination was a city in the sky he had expected to be dropped off at an airfield or perhaps a zeppelin dock.

The second floor was some sort of office. Occupying one wall was a map of the United States dotted with pushpins illustrating what appeared to be some sort of travel schedule. A table of times and dates next to the map confirmed this theory. There was a note pinned to the map. It read:

_Be prepared._  
_He's on his way._  
_You must stop him._

_-C_

A sense of unease washed over Booker. He scanned the room more carefully and noticed a cigar butt on the floor. Lucky Strike. It was warm to the touch.

The creak of an old floorboard gave away the assailant as he rushed out from his cover behind a filing cabinet, brandishing a wrench. In one fluid motion indicative of a lifetime of experience, Booker turned, drew his pistol, cocked it, and fired a round into the man's forehead. The man staggered forward another half-step before dropping to the floor with a heavy thud.

After confirming the man was dead, Booker rifled through his pockets. While there was nothing but lint in the man's pants pockets, his left jacket pocket contained a book: Prophet: The Life and Times of Zachary Hale Comstock by Edward Gaines. Booker commandeered it for later reading. Any information on Comstock should prove useful.

Booker theorized the assailant was the lighthouse keeper since the note from the mysterious "C", which Booker assumed stood for "Comstock", had been pinned to the wall as a reminder to him. An ashtray on a nearby desk filled with Lucky Strike butts corroborated his theory. But how did Comstock know Booker was on his way? Did the Luteces sell him out? Was this part of their experiment?

As he carefully analyzed the contents of the room, studying each document in each desk and filing cabinet drawer, Booker discovered the lighthouse was indeed a point of entry to Columbia. Every document he found concerned immigration. From the names on the immigration logs, it appeared Columbia was popular with the upper crust of society. Several familiar names caught his eye: John Jacob Astor IV, John Pierpont Morgan, fellow cavalryman Theodore Roosevelt.

Satisfied with the thoroughness of his search but thoroughly unsatisfied with the dearth of meaningful answers it produced, Booker began climbing the stairs to the third floor, pistol drawn.

The third floor was empty except for a naked light bulb, a chair, and some unremarkable books. It appeared to be a makeshift library. Booker continued up the stairs, which now led to the roof. As Booker reached the roof he expected to find an airship dock but was greeted only by the forlorn lighthouse lamp. He was about to go back down to the third floor, assuming he had missed something, when he noticed the three unusually decorated bells on the door leading into the lamp room. A scroll, key, and sword respectively were carved into the bells. Booker tried ringing each bell to no result. He figured it was a signaling mechanism of some sort, but what was the correct sequence of bell-rings?

If the correct sequence was 4 arbitrary bell-rings, then there were 3^4 = 81 possible sequences. He could brute-force that. Even if the sequence was 6 arbitrary bell-rings that was still a manageable 3^6 = 729 possible sequences. But if the sequence was longer than 6 bell-rings brute-forcing the correct sequence would take an impractical amount of time.

Booker realized he could potentially cut down the search space with a constraint. From the layout of the bells he theorized it was likely that the leftmost bell would be rung some number of times, followed by the middle bell, then the rightmost bell. Perhaps each bell corresponded to a numerical digit. For example, the code 123 would be represented by ringing the leftmost bell once, the middle bell twice, and the rightmost bell three times. If this theory was correct, he could brute-force check all possible sequences (9^3 = 729) in a reasonable amount of time.

Booker then considered the fact that this lighthouse apparently served as a busy transport hub for wealthy passengers. He imagined John Jacob Astor IV would not appreciate standing around while the lighthouse keeper went through a prolonged sequence of bell-ringing. As a result it was unlikely for the code to be too complex-such as requiring more than 3 rings of any bell. So he would try those 3^3 = 27 sequences first. If that failed he would fall back to his theory about each bell representing a numerical digit. If neither method worked he would default to naive brute-forcing while making plans to ambush whomever Comstock eventually sent to check on the lighthouse keeper.

Booker prepared for a long night of bell ringing.

Left, Center, Right. Nothing.

Left, Center, Right, Right. Nothing.

Left, Center, Right, Right, Right. Nothing.

Left, Center, Center, Right. Nothing.

Left, Center, Center, Right, Right. Jackpot.


End file.
